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Lotus Europa Forums => Garage => Topic started by: TurboFource on Monday,October 03, 2022, 06:38:44 PM

Title: Twin Cam valve shim thickness?
Post by: TurboFource on Monday,October 03, 2022, 06:38:44 PM
In the Wilkins book he says Twin Cams left the factory with .100 - .120” thick valve shims yet the Lotus manual shows available shims of .065 - .090” ……  :confused:

Where are most of you at?       Looks like I am going to be from .067 - .080” …….
Title: Re: Twin Cam valve shim thickness?
Post by: BDA on Monday,October 03, 2022, 07:04:33 PM
It really doesn’t matter. You’ll have to live with the shims you can get. I’m sure Ray at r.d. or Ken at Dave Bean will a pretty complete set. In a pinch you can wet sand a few thou off a thick one.
Title: Re: Twin Cam valve shim thickness?
Post by: EuropaTC on Monday,October 03, 2022, 10:11:58 PM
As BDA says, it doesn't matter too much although most folks don't feel comfortable with very thin (under 0.060" ?) shims. The usual problem is getting very thin shims and having to grind your own down isn't a pleasant task.

From the range you quote it sounds like a normal head with standard cams and maybe one or more sessions of lapping in the valve seats, I'd be ok with that.

It also depends on your cams. I fitted a pair of VJ5 cams a year or so ago replacing the standard TC cams and although not stated I expect these were regrinds on existing Europa cams. My shims went from the 0.080"-0.90" range on the OEM cams to  0.125-0.130 inlet, 0.135-0.141 exhaust on the VJ5's.

Brian

Title: Re: Twin Cam valve shim thickness?
Post by: TurboFource on Tuesday,October 04, 2022, 03:31:01 AM
It’s a standard cam